Industry makes extensive use of fluids containing mostly water and water soluble machine coolants to continuously or periodically cool tools or equipment which have a tendency to become heated during normal operation. The fluids after a period of use often become contaminated with various water soluble and insoluble substances such as filings, tramp oils, etc. The contaminated fluids are then no longer useful as they lose effectiveness and may damage various working machine parts.
Current anti-pollution laws require that these contaminated fluid wastes be dumped at designated regional waste disposal sites so not to pollute the environment. Oftentimes the designated waste disposal sites are substantial distances from the user site. In addition, precautions must be taken to ship the contaminated waste in a safe manner. Compliance with the laws is very expensive as frequently there are large amounts of waste to be shipped.
Therefore, devices have been built in an attempt to recycle and reduce the volume of contaminated waste. Devices are known which heat contaminated fluid to the boiling point to evaporate the water and the water soluble substances contained therein into an environmentally safe vapor which is then vented into the atmosphere.
Fluid eliminators currently utilized have associated various problems. Present eliminators commonly use a heat source located directly beneath the container. As a result, the liner of the container becomes very hot since it serves as the medium for conducting the heat to the contaminated fluid. Furthermore, most contaminated fluids contain non-soluble substances which settle out of the fluid during the heating process. The non-soluble substances deposit on the bottom of the container and serve as an insulating layer for preventing the conductance of heat from the container bottom to the fluid. This reduces overall efficiency of the device. In addition, the settlings are difficult to clean from the bottom of the container as they become caked or baked onto the surface.
Another hazard related to present eliminators is the tendency to emit harmful fumes. It is very important that a proper draft be maintained at all times to draw off any and all fumes created as a result of the evaporation process.
Present eliminators tend to be bulky and cumbersome in size thereby requiring a significant amount of space for operation. This creates problems for a small shop or operator where floor space is at a premium. Often a special, extra heavy electrical feed is required or special fuels are necessary, imposing a further burden on the small operator.
Some fluid eliminators utilize centrifugal force as a means to separate out the tramp oils and other various contaminants from the fluid. However, with such eliminators, the bacteria which may be thriving in the contaminated fluid is not killed since no heat is applied during the process. This can create a significant health problem since many people are allergic to the bacteria which thrive in the contaminated fluid.
The present invention overcomes these problems by use of a novel air assisted evaporator which utilizes a unique flue structure to assure efficient heating of the fluid in addition to other advantageous features.